Giant cell carcinoma (GCC) is a highly aggressive variant of sarcomatoid carcinoma of lung. [1] Morphologically, they are composed of anaplastic and pleomorphic bizarre giant cells. [2] Ovarian tumors with osteoclast type giant cells resembling giant cell tumor of bone are reported. [3],[4] However, ovarian carcinoma resembling GCC of lung is extremely rare. [5] We present a rare case of ovarian carcinoma resembling GCC lung. A 49-year old woman presented at our institution with weight loss of 3-months duration. On ultrasonography, she had bilateral adenexal masses; left larger than the right side. There was no free fluid in abdomen, liver, spleen, cervix and uterus was normal. Her cervical, endometrial and pouch of Douglas smears were normal. Except raised serum LDH, her biochemical markers were within normal limits. Chest X-ray was normal. CT abdomen and pelvis revealed bilateral adnexal masses; right side was cystic and measured 5.3 × 3.9 × 3 cm. while the left side measured 13 × 10 × 8 cm. On laprotomy, the frozen section from the left adnexal mass revealed poorly differentiated malignant tumor. Hence, she underwent trans-abdominal hysterectomy with bilateral salpingo-oophorectomy along with peritoneal samplings, bilateral pelvic lymph node dissection and omentectomy. The left ovary was adherent to the sigmoid colon and was dissected out. Macroscopically, tumor was cystic haemorrhagic. Right ovary was cystic and was filled with clear fluid. The uterus, tubes and omentum were normal. Microscopically, tumor was composed of solid sheets of cohesive large polygonal cells with abundant pale eosinophilic to clear cytoplasm [Figure 1]A or discohesive pleomorphic mono to multinucleated tumor giant cells along with large number of inflammatory cells [Figure 1]B. The giant cells were large (50-150 microns), with bizarre nuclear appearance. Occasional giant cells showed emperipolesis of neutrophils [Figure 1]C. Osteoclast types of multi-nucleated giant cells were not seen. Mitosis was increased. No foci of other tumor types like mucinous or serous carcinomas of ovaries, choriocarcinomas, malignant germ cell tumors, malignant melanomas, angiosarcomas were found.

The tumor stage at the time of diagnosis was 1C and the patient was started on adjuvant chemotherapy for ovarian carcinoma. However, after five cycles, she developed mucus discharge per rectum. CT scan revealed recurrent mass in the pelvis infiltrating the bowel indicating aggressive behavior of the tumor. The patient was started on treatment for refractory epithelial carcinoma. As giant cell tumors have aggressive clinical course, their recognition is important for management of the patients.